The subject matter described herein relates to ultrasound imaging systems and methods.
Some known ultrasound imaging systems are used to acquire three-dimensional images of a periodically moving body, such as a beating heart. These systems may employ spatio-temporal image correlation (STIC) to generate a set of three-dimensional images at various phases of the periodic movement of the heart. In order to acquire sufficient image data to create the three-dimensional images, the transducer elements in an ultrasound probe are slowly mechanically steered across the heart. For example, the transducer elements may be mechanically swept across the heart such that many ultrasound pulses are transmitted toward the heart at various elevational angles and resulting echoes of the pulses off of the body are received. Ultrasound image data is generated based on the received echoes.
The transducer elements can be slowly swept over a range of elevational angles (such as 0 degrees to 20 degrees) while the ultrasound image data is acquired at a relatively fast frame rate. As a result, a considerable amount of ultrasound image data is acquired. The fast frame rate permits the systems to acquire ultrasound image data during the several phases of the periodic motion of the heart. The ultrasound image data is reconstructed into the three-dimensional images based on when and where the ultrasound image data was acquired. For example, the ultrasound image data that is acquired during a common phase of the periodic motion of the heart at different spatial locations may be combined into a three-dimensional image.
However, with some relatively fast moving bodies, such as fetal hearts, image artifacts may be generated in the three-dimensional images. For example, a fetus in a mother's womb may move around, thereby making it difficult to obtain spatially consistent ultrasound image data during one or more of the phases of the periodic motion of the heart. The position of the heart may change relatively rapidly during the sweep of the transducer elements across the heart and cause spatially inconsistent or incoherent ultrasound image data to be acquired during a common phase of the periodic motion of the heart.
A need exists for improving the acquisition of ultrasound image data of periodically moving bodies to generate one or more ultrasound images.